(362b) Latent Heat Trapping in Phase Switching Liquids

Latent
Heat Trapping in Phase Switching Liquids

Preventing
ice from forming on functional surfaces is a major engineering concern. Industrial
strategies to mitigate such hazards include active mechanical, chemical, and electro-thermal
deicing techniques that are energy and cost intensive.  In the current study, we show that the use of
certain phase change materials, which are in liquid state under ambient
conditions and have melting point higher than the freezing point of water,
referred herein as phase-switching liquids (PSLs), can delay
condensation–frosting lasting up to 300 longer in bulk state compared to
conventional surfaces under identical environmental conditions. The freezing
delay is primarily a consequence of the release of trapped latent heat due to
condensation, but is also affected by the solidified PSL surface morphology and
its miscibility in water. We show that regardless of surface chemistry, PSL coated
surfaces exhibit low droplet adhesion when operated below the corresponding
melting point of the solidified PSLs, engendering ice and frost repellency even
on hydrophilic substrates. Finally, we discuss how solidified PSL surfaces can
display varying degrees of optical transparency, can repel a variety of
liquids, and self-heal upon physical damage.

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Figure 1. Exceptional anti-icing performance by latent heat trapping in
Phase Switching Liquids